填料协同增强增韧光固化树脂基口腔材料的制备、性能及生物力学评价

A filler synergistic toughening light-curig resin-based dental material:preparation,performance and biomechanical evaluation

背景:光固化复合树脂由于色泽美观、优良的物理、化学性能及操作简单等在牙科缺损修复中得到应用。但是,复合树脂由于力学性能不足容易引起复合体折断,导致临床使用难以达到预期治疗效果。目的:探讨填料协同增强增韧光固化树脂基口腔材料的制备方法、性能及生物力学特征。方法:以原子转移自由基聚合方法对纳米二氧化硅进行表面接枝聚甲基丙烯酸甲酯(SiO_2-PMMA)改性,获得接枝SiO_2-PMMA,利用同轴静电纺丝方法制备聚丙烯腈/聚甲基丙烯酸甲酯核-壳纳米纤维,以铜网作为接收装置获得具备网格结构的二维乳酸-羟基乙酸共聚物纳米纤维膜。以硅烷偶联剂为原乙酯前驱体溶胶-沉淀法制备多尺度、多维度填料,采用硅烷偶联剂进行改性。将接枝SiO_2-PMMA核-壳纳米纤维、梯形聚硅氧烷材料与光固化树脂基体进行复合,比较两种复合树脂材料的力学性能、体积收缩率、毒性、降解性能等。结果与结论:(1)复合树脂断裂形貌的电镜表征:填料接枝SiO_2-PMMA核-壳纳米纤维在光固化树脂基体中能较好的分散,团聚现象相对较少,存在单分散现象;而梯形聚硅氧烷材料在光固化树脂基体中分散不均匀,且在复合树脂中甚至出现团聚现象;(2)弯曲强度、弯曲模量及断裂功:填料接枝SiO_2-PMMA核-壳纳米纤维光固化树脂基口腔材料的弯曲强度、弯曲模量及断裂功显著高于梯形聚硅氧烷材料光固化树脂基口腔材料(P<0.05);(3)体积收缩率:填料接枝Si O2-PMMA核-壳纳米纤维光固化树脂基口腔材料的体积收缩率低于梯形聚硅氧烷材料光固化树脂基口腔材料(P<0.05);(4)性能测定:填料接枝Si O2-PMMA核-壳纳米纤维光固化树脂基口腔材料吸水性及细胞毒性A值高于梯形聚硅氧烷材料光固化树脂基口腔材料(P<0.05),而溶解值低于梯形聚硅氧烷材料光固化树脂基口腔材料(P<0.05);(5)提示制备的填料协同增强增韧光固化树脂基口腔材料具备优良的性能和生物力学特征。

BACKGROUND： Light-curing composite resins have been applied in the dental repair due to its beautiful color, excellent physical and chemical properties and easy to operation. However, its insufficient mechanical properties tend to cause composite fractures, resulting in undesired clinical efficacy.OBJECTIVE： To investigate the preparation, properties and biomechanical performances of filler-co-augmented photo-curable resin-based oral materials.METHODS： The nano-silica surface-grafted with poly（methyl methacrylate） （PMMA） was obtained by atom transfer radical polymerization. Co-electrospinning was used to prepare the acrylonitrile/PMMA core-shell nanofibers, and a two-dimensional lactic acid-glycolic acid copolymer nanofiber membrane with a lattice structure was obtained using a copper mesh as a receiving device. The multi-scale and multi-dimensional packing was prepared by sol-precipitation method with silane coupling agent as a raw ethyl ester precursor, and further modified using silane coupling agent. The mechanical properties, volumetric shrinkage, toxicity, and degradation properties of the light-curing resin grafted with SiO2-PMMA were compared with those of the light-curing resin combined with trapezoidal polysiloxane materials grafted with methyl methacrylate. RESULTS AND CONCLUSION： （1） Characterization of the composite resin under scanning electron microscope： the filler SiO2-PMMA core-shell nanofibers dispersed well in the light-curing resin matrix, in the presence of monodisperse phenomenon and less aggregation phenomenon. However, the trapezoidal polysiloxane material in the light-curing resin matrix dispersed unevenly, in the presence of reunion phenomenon. （2） The flexural strength, flexural modulus and fracture work of the light-curing resin grafted with SiO2-PMMA core-shell nanofibers were significantly higher than those of the trapezoidal polysiloxane-based light-curing resin （P 〈 0.05）. （3） The volume shrinkage of the light-curing resin grafted with SiO2-PMMA core-shell nanofibers was lower than that of the trapezoidal polysiloxane-based light-curing resin （P 〈 0.05）. （4） Compared with the trapezoidal polysiloxane-based light-curing resin, the water absorption and cytotoxicity （absorbance value） of the light-curing resin grafted with SiO2-PMMA core-shell nanofibers were significantly higher than those of the trapezoidal polysiloxane-based light-curing resin （P 〈 0.05）, while the solubility of the light-curing resin grafted with SiO2-PMMA core-shell nanofibers was lower （P 〈 0.05）. It is concluded that the prepared light-curing resin grafted with SiO2-PMMA core-shell nanofibers has excellent properties and biomechanical properties.